Our Blog at Oversitesentry.com goes over in some detail the new XSS attack vector.
An exifdata image could include scripts that may affect you or your website visitors in unimagined ways.
Only the evil hackers with their money making ventures causing untold damage and their imagination creating havoc, so only time will tell what attacks will be coming our way.
Essentially whenever a new type of attack is uncovered:
1. are you susceptible? Is your website accepting images automatically?
2. Is your blog software susceptible?
3. When downloading images, a separate process of checking the details of the images should be done from unknown sites.
Contact Us if you have any questions on this issue or other Security issues.